Multiplex fuse plug



Sept. 1, 1953 W. H. WILSQN MULTIPLEX FUSE PLUG Flled Feb 26 1953 a IllilII! Illillllllillll INVENTOR ATTORNEY Patented Sept. 1, 1953 UNITEDSTATES PATENT OFFICE MULTIPLEX FUSE PLUG Walter H. Wilson, Mansfield,Ohio Application February 26, 1953, Serial No. 339,019

3 Claims.

This invention relates to a multiplex fuse plu and has for an object toprovide an improved multiplex fuse plug having a multiplicity ofseparably blowable fuse portions of a single continuous fuse element anda corresponding multiplicity of intermediate off positions, thusproviding a fuse which can be used for a plurality of circuit overloads,and which can be readily operated to an off position, irrespective ofwhich fuse portion is in operation, without the necessity of removingthe fuse to interrupt the circuit while working on the circuit line.

A further object of this invention is to provide an inexpensivemultiplex fuse capable of several repeated uses, and wherein the blownfuse element containing cup may be easily replaced, thus making the fusebody available for subsequent series of uses.

A further object of this invention is to provide a multiplex fuse havinga multiplicity of separate use element portions which are separably use---ble and blowable, each fuse element portion being in a separatechamber, and a hollow plug body into which the blown fuse may explode touse up its energy without affecting or blowing the fuse element portionsin the remaining fuse element portion chambers.

A further object of this invention is to provide a multiplex fuseprovided with an off position located adjacent each on position.

A further object of this invention is to provide a multiplex fuse bodyand cap both made of insulating material such as glass or suitableplastic within which the conductor elements may be permanently molded orsecured, and provided with a readily replaceable continuous fuse elementfor providing a series of fuse element portions.

With the foregoing and other objects in view, this invention comprisesthe combination, construction and arrangement of parts hereinafter setforth, claimed and disclosed in the accompanying drawings, wherein:

Fig. l is a side elevational view of the multiplex fuse plug of thisinvention,

Fig. 2 is a top plan view of Fig. 1.

Fig. 3 is a partly sectional view on line 33 of Fig. 2.

Fig. 4 is a plan sectional view of the plug cap alone on line 4-4 ofFig. 3.

Fig. 5 is a plan view of the plug body, showing a fragmentary fuseelement in its relative positions.

Fig. 6 is a sectional view on line 6-6 of Fig. 5.

There is shown in said drawings the multiplex fuse plug ill of thisinvention comprising a plug 2 body l I and a rotatable plug cap l2 bodyof suitable insulating material, such as glass or other suitableinsulating material capable of being molded to the desired shapes.

The plug body It has an open cupped end M having a floor l5 from which acounterbore extends providing a thimble shaped shell it which iscompletely hollow as at I? except for the presence of a conductor 18which connects to a contact head 29. at the bottom end thereof, and atits other end is molded through the floor I5 to extend within the innerwall 2| of the cupped end It and provide a first contact brush 22.

Also secured on the shell I6 is a contact ferrule threaded in the usualmanner, and having a conductor portion 24 extending therefrom and moldedthrough floor [5 and terminating in a second contact brush 25 on theinner side of cupped end wall 2! and angularly spaced a suitabledistance from the first contact brush 22. An indicia mark 26 is providedon the rim 2'! of the cupped end It adjacent this second contact brush25.

The rotatable plug cap I2 is likewise made of suitable and preferablytransparent insulating material such as glass or plastic, and is cupshaped as at 39 and of a size to have its cup rim 3! nest within thecupped end It of plug body H and be supported on the plug body floor It.The cap 12 is rotatably and removably held in the nested position bymeans of removable screws 32 threaded through the plug body cupped endwall 21 into a cooperating circumferential groove 33 in the cap 12.Obviously, removing the screws 32 permits the separation of the body Hand cap 12. A handle 34 central of the cap i2 and exterior thereofprovides for ready manipulation and rotation of the cap I2.

The cup 30 of the plug cap i2 is divided into a plurality of separatechambers 35 by radially extending webs 36 meeting at a center core 37and terminating in the cup rim 3!. The webs 36 are angularly'spacedapart the same angular spacing as the two brush contacts 22 and 25.Molded in and extended through the wall of cup 30 at 33, so as to extendin chord position across at least less than one of all the chamber 35,is a continuous fuse element ii) thus providing contact portions llexternal of the plug cap cup rim 3! and fuse element portions 32 in thechord position within the chambers 35.

As shown, the contact brushes 22 and 25, and thus also the chamber webs36 and fuse contact portions 4|, are sixty degrees apart, therebyproviding five fuse element portions 42, each in a acsaecs separatechamber, and one chamber with no fuse element portion. The exterior topof the plu cap I2 is marked with angularly spaced indicia 1 to inclusiveand 0 on corresponding radial lines as at 33, and intermediate thereof,ofi indicia M is located, the indicia being so placed with relation ofthe fuse contact portions ll that when the number indicia 63 is adjacentthe marking indicia 26 on the plug body rim 217, a fuse element portionA2 is in operative circuit protective position, with two adjacent fuseelement contact portions ill in contact with the contact brushes 22 and25, and when any one of the off indicia M is adjacent the marker indicia2%, the fuse element contact portions ii are in the dotted line position4! interrupting the circuit, as when it is desired to work .on thecircuit line.

In operation, when a circuit is overloaded, the fuse element portion 32in the circuit position blows through the open side of its chamber intothe open hollow space ll of shell it to thus expend its and thus refrainfrom overheating and blowing any other fuse element portion. When thecause of the overloaded circuit has been located and remedied, thecircuit is restored by manipulating the handle to partially rotate plugGap i2 and bring the next fuse el ent portion 32 into circuit position-If the circuit line is to be worked at any time, the fuse need not beremoved, but the cap is merel rotated to the adjacent on position.

When all the fuse element portions have been blown, the cap i2 may beremoved by removing the screws 32 from .the groove ...nd a new cap witha new fuse therein be substituted, or the entire plug may be replaced.

While the device has been shown and the structure described in detail,it is obvious that this invention is not to considered as limited to theexact form disclosed, and that oh ages in detail and construction may betherein within the scope of what is claimed, without departing from thespirit of this invention.

Having thus set forth disclosed the nature of this invention, what isclaimed is:

l. A multiplex fuse plug comprising a body of insulating material havingan open end having a floor from which a counterbore extends into thebody providing a hollow thiinble shaped shell, a contact head securedthrough the bottom of said shell, a conductor extending from saidcontact head and terminating within inner side wall of said cupped endadjacent fro-or providing a first contact brush, a contact rrule onsaid. shell having a conductor portion. exten ing therefrom through saidfloor to inner side wall of said cupped end providing a second contactrush angularly spaced from said first contact brush, an open cup-shapedplug cap of insulating material nesting within cupped end of said bodyadjacent said iioor, means for reniovabl and rotatably mounting said innesting position in said plug cupped end, said plug cap having aplurality of angularly spaced radially extending webs dividing said opencupshaped cap into separate chambers open on the side toward said hollowthirnble shaped shell, a continuous fuse element secured through the cupwall of each separate chamber externally of each radial web andinternally of at least one less than all of said separate chambers, saidand second contact brushes being angularly spaced the same spacing assaid radial webs, manual rotating handle means on said plug cap exteriorthereof, multiplex fuse indicating indicia and intermediate 01findicating indicia on said cap and a cooperating indicia on said plugbody, whereby said plug cap may be rotated to position any two adjacentexternal portions of said fuse element in contact with said first andsecond brush contacts or to an 01f position between said contacts, theinternal fuse element portion within the chamber between said contactedexternal portions blowingwhen overloaded into said hollow body shellwithout blowing the fuse'portions in the other chambers.

2. A multiplex fuse plug comprising a body of insulating material havingan open cupped end having a floor from which a counterbore extends into:the body providing a hollow thirnble shaped shell, a contact headsecured through the bottom of said shell; a conductor extending iromsaid contact head and terminating within the inner side wall of saidcupped end adjacent said floor providing a first contact brush, acontact ferrule on said shell having a conductor portion extendingtherefrom through said fiOOr to within the inner side wall of saidcupped end providing a second contact brush angularly spaced from said.

first contact brush, an open cup-shaped plug cap of insulating materialnesting within said cupped end of said body adjacent said floor, meansfor rotatably mounting said cap in nesting position comprising stud-means, screws extending from the inner side of said cupped end into acooperating circumferential groove in said plug cap, said plug caphaving-a plurality of angularly spaced radially extending webs dividingsaid open cup- .shaped cap into separate chambers open on the sidetoward said hollow thirnble shaped shell,

each separate chamber having a continuous fuse element molded in andextending through its cup Wall externally of each-radial web andinternally of at least one less than all of said separate chambers, saidfirst and second contact brushes'being angularly spaced the same spacingas radial webs, manual rotating handle -neans on said plug cap exteriorthereof, multiplex fuse indicating indicia and intermediate offindicating indicia on said cap and a cooperating indicia on said plugbody, whereby said plug cap may be rotated to position any two adjacentexternal portions of said fuse element in contact with sa first andsecond brush contacts or to an 0. position betweensaid'contacts,theinternal fuse element portion within the chamberbetween said contacted external portions blowing when overloaded intosaid hollow body shell without blowing the fuse portions in the otherchambers.

3. A multiplex fuse plug comprising a body of insulating materialhaving. an open cupped end having a door from which a coun erboreextents into the body providing a hollow'thimble shaped shell, a contacthead secured through the better.

of said shell, a conductor'extending from said first contact brush, anopen cup-shaped plug .cap a of insulating material nesting within cuppedend of said bodyadjacent said floor, means for removabl and rotatablymounting said cap in nesting position comprising. stud screv s threadedthrough the side of said plug cupped end :into a cooperating--circumferential groovein said plug cap, said plug cap having aplurality of angularly spaced radially extending webs dividing said opencup-shaped cap into separate chambers open on the side toward saidhollow thimble shaped shell, each separate chamber having a continuousfuse element secured in and extending through its cup wall externally ofeach radial web and internally of at least one less than all of saidseparate chambers, said first and second contact brushes being angularlyspaced the same spacing as said radial webs, manual rotating handlemeans on said plug cap exterior thereof, multiplex fuse indicatingindicia and intermediate 011? indicating indicia on said cap and acooperating indicia on said plug body, whereby said plug cap may berotated to position any two adjacent external portions of said fuseelement in contact with said first and second brush contacts or to anoff position between said contacts, the internal fuse element portionwithin the chamber between said contacted external portions blowing whenoverloaded into said hollow body shell without blowing the 10 fuseportions in the other chambers.

WALTER H. WILSON.

No references cited.

